TY - BOOK AU - Abramson,Joseph Herbert TI - Survey methods in community medicine: an introduction to epidemiological and evaluative studies SN - 0-443-02021-3 U1 - 362.1'072 PY - 1979/// CY - New York PB - Churchill Livingstone KW - Estudios de Salud KW - Salud Pública KW - Investigación ER -